EUGENE VOLOKH: Can private employers fire employees for going to a white supremacist rally?
A substantial minority of states, though, do ban discrimination based on political activity, especially off-the-job political activity; some cities and counties do as well. I cataloged them in 2012 in my article “Private Employees’ Speech and Political Activity: Statutory Protection Against Employer Retaliation“; since then, Utah has enacted a similar statute as well.
a. Some statutes ban employers from firing employees for “political activity,” including ideological advocacy generally and not just election-related politics. California, Colorado, Louisiana, Minnesota, Missouri, Nebraska, Nevada, South Carolina, Utah and West Virginia seem to fall in this category; there are similar ordinances in Seattle and Madison, and a New Mexico statute may also fit here, though it’s a bit more ambiguous.
b. Connecticut protects employees from retaliation for their speech more broadly.
c. Colorado and North Dakota ban employers from firing employees for any off-duty lawful activity; that would cover speech as well.
Even “at will” states are not always truly “at will.”
Ironically, of course, these protections were mostly put into place by lefties.